1. Field of the Invention
The present invention relates to an information processing apparatus such as a personal computer that has a built-in HDD (Hard Disk Drive) and a head evacuation processing method for the built-in hard disk drive.
2. Description of the Related Art
Information processing apparatuses such as a portable personal computer use an HDD (Hard Disk Drive) as a data storage apparatus in many cases. In the HDD, since a head slightly floats from a surface of a disk due to an airflow caused by a disk rotation, when a large acceleration caused by an impact is applied, there is a possibility that the head would be brought into contact with a disk recording surface depending on the magnitude of the acceleration to thus break the disk. For such a reason, the HDD is normally equipped with a protective function for preventing, by moving the head from a disk recording area to an evacuation position at a time an impact is applied, the head and the disk recording surface from coming into contact with each other and the disk from breaking.
In many cases, an acceleration sensor, particularly a triaxial acceleration sensor that is capable of detecting accelerations in triaxial directions at the same time, is used for detecting an impact. As an example of a system that performs head evacuation processing using such a triaxial acceleration sensor, there are known a system that performs head evacuation processing when any of the accelerations in the triaxial directions detected by the triaxial acceleration sensor exceeds a preset threshold value and a system that executes the head evacuation processing once a drop (gravity-free state) is detected based on the acceleration values in the triaxial directions (see, for example, Japanese Patent Application Laid-open No. 2005-346840).